The Brazilian sustained ligament damage during the Champions League clash with Olympiakos last week.
The 28-year-old’s injury requires surgery to repair.
“Arsenal Football Club can confirm that, following investigations and subsequent medical opinions by club specialists, left-back Andre Santos will have surgery to repair ligament damage in his right ankle sustained in the game against Olympiakos last week,” read the statement released on the club’s official website.
“Andre will have surgery in Brazil this week and is expected to be out for around three months.
“Everyone at the club wishes him well.”
